The Japanese marten (Martes melampus) is a marten species endemic to Japan. Description It is in length typically, not counting a long tail, and between in weight. Males are generally larger than females. The pelage varies in color from dark brown to dull yellow with a cream-colored throat. Diet and behavior Both males and females are territorial, and the size of each individual's territory depending on food availability. The Japanese marten is omnivorous, preferring meat from fish, frogs, and small birds and mammals, but consuming insects, fruit, and seeds when necessary. Taxonomy The two confirmed subspecies of Japanese marten are: M. m. melampus lives on several of the Japanese islands. M. m. tsuensis is endemic to Tsushima Island. It is most closely related to the sable (M. zibellina), with which it is sympatric on Hokkaido. Distribution The Japanese marten's presence on Hokkaido and Sado islands are due to introductions. It has been recorded in South Korea, but no locality details prove a wild origin and no native population has been confirmed. Reproduction and lifecycle The Japanese martens' breeding season occurs between March and the middle of May. They usually produce one offspring; however, they can have up to five kits per mating season. The offspring are born blind and deaf. As a mammal, the female produces milk for her young offspring, but by 3–4 months of age, the kits are able to hunt and soon leave their mother. Sexual maturity occurs between 1 and 2 years old. Average lifespan in the wild is unknown, although a specimen in captivity lived for a little more than 12 years. After reaching maturity, young martens often try to establish their territory. They mark their territory with scent marking. Habitat Japanese martens live in boreal forests in much of Japan's mainland. In the winter, martens tend to go to the forests where they can get the most prey. They tend to choose well-established forests because of the ways the creatures have specialized and due to their long lifespan. As such, martens likely are valuable in assessing the health of the forest. However, in the summer, their habitat and diet become much more generalized, allowing them to live in a much more varied environment. Ecology One of the biggest roles martens play in the environment is seed dispersal. Many fleshy fruits rely on birds and bats to disperse their seeds; however, in more northern climates,